1. Technical Field
The present application claims priority to Korean Patent Application No. 10-2016-0021748 filed on Feb. 24, 2016 in the Republic of Korea, the disclosures of which are incorporated herein by reference.
The present disclosure relates to an inverter, and more particularly, to an inverter capable of attenuating noise during operation by structurally separating a signal unit from a power unit.
2. Description of the Related Art
Typically, a motor drive device is supplied with power from a commercial power source. Then, the motor driving device varies the voltage and frequency of the power and supplies the varied power to the motor, thereby controlling the speed of the motor with high efficiency. A conventional motor configured as above is described below.
FIG. 1 illustrates a conventional inverter and power and signal flows thereof, and FIG. 2 is a perspective view illustrating the conventional motor drive seen from another side.
Referring to FIGS. 1 and 2, the conventional inverter includes a heat sink 10 and a plurality of circuit boards 20, 30, 40, 50, which are installed on a base.
The heat sink 10 is installed on the base.
The circuit boards 20, 30, 40, 50 are disposed on a middle base, which is disposed on the heat sink 10.
The circuit boards 20, 30, 40, 50 include a power board 20 disposed on the middle base, a cap board 50 disposed on the power board 20, a control board 30 perpendicularly connected to the power board 20, and an I/O board 40 disposed on control board 30.
In FIG. 1, the hollow arrow indicates flow of a main power along an input terminal 31, a rectification part 22, a DC link 27, an inverter part 23, and an output terminal 32.
The solid arrow indicates an SMPS secondary power source 25, which supplies power to the control board 30, a gate drive, and a sensing and protection circuit 26.
The dotted arrow indicates signals of a controller 24 of the control board 30, the gate drive and the sensing and protection circuit 26.
In the case of power flow and signal flow of the conventional inverter described above, interference occurs between the output of the rectification part 22 and the output of inverter part 23 due to intersection of main power therebetween.
That is, for the conventional inverter, a power terminal, a power unit such as PIM, and a signal unit are installed on the same board.
Accordingly, the signal of the conventional inverter is structurally subjected to interference by the flow of main power as described above.
Referring to FIG. 2, the conventional I/O board 40 and the control board 30 are electrically connected to each other through a wire 60 for signals, thereby forming a signal line.
The I/O board 40 is connected to the power board 20 through a ground wire 70 formed on the corresponding board, and the ground wire 70 connected to the power board 20 is extended and connected to the heat sink 10.
According to the configuration described above, the conventional inverter is structurally weak as it uses wires such as a signal wire capable of functioning as a noise antenna and a ground wire.
In addition, in the conventional cases, as the wires are used, fire may be caused by contact between the wires and a component generating heat in the process of assembling a product. Thereby, damage to the product and malfunctioning may occur.
Prior art documents related to the present disclosure include Korean Patent Application Publication No. 10-2007-0053940 (Publication Date: May 28, 2007). This document discloses a flexible print circuit board preventing circuit interference among the layers.